Supported file formats:
Free plan: mp3, m4a.
Unlimited Audio Plan: mp3, m4a, ogg, mpg, zip, pdf.
Unlimited Plus and above plans: mp3, m4a, ogg, mp4, m4v, zip, pdf, mpg.
Supported images formats:
.jpg, .gif, and .png.
The recommended stereo bit rate and sample rate for audio files:
Stereo Bit Rate: 128 kbps
Sample Rate: 44.1 kHz
The maximum allowed single file size: 3GB.
The maximum allowed single image file size: 1 MB.
In order to be better compatible with iTunes, iPad/tablets, and mobile, we highly recommend you use Mp3 or H.264 based mp4 and m4v.